In a written statement, Band said: “President Clinton is in good spirits, and will continue to focus on the work of his foundation and Haiti’s relief and long-term recovery efforts.”

Clinton’s daughter, Chelsea Clinton, was with her father, according to spokeswoman Julie Goldberg.

His wife, Secretary of State Hillary Clinton, left the White House after a meeting in the Oval Office and headed to New York, a State Department official said.

Hillary Clinton’s planned trip to the Middle East will be delayed until Saturday, a senior U.S. official said. She had been scheduled to depart Friday afternoon.

A spokesman for former President George W. Bush, who has been working closely with Clinton on Haiti earthquake relief and recovery efforts, said in a statement that Bush spoke with Chelsea Clinton on Thursday afternoon and “was glad to hear that her father is doing well and that his spirits are high.”

Clintonhasn’t left the public eye since he departed the White House in 2001, maintaining an active schedule devoted to global philanthropic interests and speeches.

Since the January 12 earthquake that hit Haiti, he has traveled there twice in his latest role as the U.N. special envoy for the ravaged nation. On February 3, U.N. Secretary-General Ban Ki-moon placed Clinton in charge of overseeing aid and reconstruction efforts there. Clinton also attended the World Economic Forum in Davos, Switzerland, in January.

Clinton underwent quadruple bypass surgery in 2004 at New York-Presbyterian. Doctors in 2005 removed scar tissue and fluid that had built up following that surgery.

David Gergen, CNN senior political analyst, said that Clinton was “exhausted” and had a cold after returning from his second trip to Haiti earlier this month.

Sources close to Clinton said the former president is hard to slow down and has ignored friends’ advice that he take better care of himself.

“He still works long days and stays up very, very late,” a friend of Clinton’s said. “He has gone from a frenetic pace to what most people would consider a frenetic pace.”

McAuliffe said Clinton apparently was on a conference call about Haiti as he was being wheeled into the operating room Thursday.

“He was working right up until the last second,” he said.

The friend said that although Clinton’s diet has improved since his 2004 quadruple bypass surgery, “he certainly indulges every once in a while consistent with past behavior, [for example] fries with his fish.”

Dr. Jonathan Reiner of George Washington University, cardiologist for former Vice President Dick Cheney, said the symptoms Clinton had Thursday sound typical of angina or ischemia, which happens when blood flow to the heart muscle is decreased by a blocked coronary artery.

“The president had new symptoms suggestive a blockage of one of his arteries or a blockage in one of his bypass grafts, which is probably more likely,” he said.

After bypass surgery, bypass grafts don’t always have an indefinite longevity, Reiner said. It’s not uncommon for a bypass graft to have a problem years after surgery, he said.